Alarm devices offer a wide variety of features and methodology for notifying a person of an event. Alarms may be triggered by the occurrence of an unscheduled event, for example alarm sounds broadcast over public address system speakers in a fire station to wake firefighters to respond to an immediate request for assistance for health or safety emergencies occurring during night time hours. Applications also include “alarm clocks” that wake a person from sleep through sound, touch or other stimulus inputs in response to the occurrence of a scheduled or designated time of day. For example, a morning wake-up time or range of times may be chosen to generate an alarm that occurs early enough to enable an alarm device user to wake and get dressed and otherwise get ready to travel to an employer by the beginning of a work day.
People require regular periods of sleep of sufficient time and quality to maintain proper body function and health, most commonly during the nighttime. Sleep periods comprehend a variety of different and distinct patterns or cycles, including rapid-eye-movement (REM) sleep and non-rapid-eye-movement (NREM) sleep cycles. REM sleep is often considered “active sleep” and is identifiable by characteristic lower-amplitude (small), higher-frequency (fast) waves and alpha rhythms as determined by electro-encephalogram (EEG) data relative to NREM sleep, as well as the eye movements for which it is named. NREM sleep may be further described by three distinct and different stages: N1, N2, and N3. In the progression from stage N1 to N3, brain waves become slower and more synchronized, and the eyes remain still. In stage N3, the deepest stage of NREM, EEGs reveal high-amplitude (large), low-frequency (slow) waves and spindles. This stage is referred to as “deep” or “slow-wave” sleep. (See “Healthy Sleep: Natural Patterns of Sleep,” Division of Sleep Medicine at Harvard Medical School, August 2016, http://healthysleep.med.harvard.edu/healthy/science/what/sleep-patterns-rem-nrem.)
Waking from sleep may be difficult. Users of alarms to trigger wakefulness may feel that they have not had a sufficiently long, or sufficiently restful (uninterrupted) period of sleep to meet their personal, restorative needs. Accordingly, users commonly delay waking times by the use of “snooze alarm” routines that silence alarms for a designated delay period of minutes, at the lapse of which the alarm again sounds, wherein the user may go back to sleep and enjoy an additional period of sleep during the delay period, in order to more gradually awaken over the snooze time period, or to perceive that they have enjoyed additional sleep time and thereby feel more refreshed and ready to wake up.
Being woken by alarms or other stimuli at unpredictable times that interrupt user sleep patterns and schedules may have debilitating effects on users, leaving users feeling tired and unrefreshed. Experiencing a jarring or frantic start to the day may leave a person feeling relatively more poorly later in the day, with lower perceived levels of energy, creativity, spontaneity, concentration, motivation, tolerance for stress, etc., relative to awaking from sleep naturally, such as at the end of an appropriate sleep cycle in response to internal biological clock and sleep-wake homeostat system functioning. (See “You Could Wake Up Naturally to a More Energized Day: Small Changes Can Mean BIG Energy,” M. Kramer, Sparkpeople, August 2016, http://www.sparkpeople.com/resource/wellness_articles.asp?id=329.)